[Operators] On indirection in SRV record targets

Dave Cridland dave at cridland.net
Mon Sep 21 04:15:29 CDT 2009


On Sat Sep 19 15:24:27 2009, Matthew Wild wrote:
> According to RFC 2782, SRV record targets are *not* allowed to be
> "alias" records, this includes CNAMEs and PTRs for example. I just
> made a change (not yet checked in) to Prosody which  
> (unintentionally)
> would render domains configured in such a way unreachable. I  
> restarted
> my server with the new code for testing to find a handful of my
> contacts can no longer accessible.

Wikipedia has a very good primer on CNAME (and DNAME, its scarier  
cousin).

I'd particularly refer you to  
http://mengwong.com/misc/rfc1912-is-wrong.html though, which refers  
to RFC 974:

"
    Of course, by the robustness
    principle, domain software should not fail when presented with  
CNAME
    chains or loops; CNAME chains should be followed and CNAME loops
    signalled as an error.
"

So I'd say that settles your question of what the default should be.  
:-)

Dave.
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